Electromechanical sound reproducer and amplifier



Feb. 14, 1928. 1,658,798

c. K. CREGIER ELECTROMECHANICAL SOUND REPRODUCER AND AMPLIFIER Filed June 25, 192.3 2 Sheets-Sheet 1 Feb..l4, 1928. 1,658,798

c. K. CREGIER ELECTROMECHANICAL SOUND REPRODUCER AND AMPLIFIER Filed June 2 1923 2 Sheets-Sheet 2 1231110772507 Charms CPQg/LW 4y ,SWQ MW device of the character de Patented Feb. 14, 1928.

CHAR-LES K. GREGIER, OF GLEN ELLYN, ILLINOIS.

ELECTROMECHANICAL SOUND BEPRODUCER AND AMPLIFIER.

. 'Application filed June 25, 1923.

This inviu'ition relates to improven'ients in electro-mechanical sound rcproduoers and amplifiers and been more especially designed a loud-speaking unit for radio receiving purposes.

One object of the invention is to provide a device of the class described which shall be capable of enormou y amplifying the reproductions of an ordinary telephone receiver while at the same time preserving the timbre and one characteristics thereof to a degree of perfection never heretofore realized in the use of devices of this kind.

Another object is to pro ide means in a bed whereby the same may be inoin'ited upon and operated by the turntable of ordinary phono graph, there being a Itll'lllQl provision of means whereljiy the device when so mounted may be connected directly to the tone arm thereby utilizing the of such phonograph.

' passages thereof, 1n-

various ampli'.

A further objec is to simplify and improve general v both the construction and operation of m device shown in my prior Patent l\ 1.,1l2.. 87l: of June 15, 1915.

Other objects and advantages will be apparent to those skilled in the art from a reading of the following specification taken in connection with the accompanying drawings, wherein one form of the invention is illustrated.

In the drawings,-

Fig. 1 is a top plan view of a phonograph showing a device constructed in accordance with the present invention, operatively mounted upon the turntable thereof and connected to the tone arm;

Fig. 2 is a sectional view of the device taken on the line 2--2 of Fig. 1;

Fig. 3 is a sectional view taken on the line 33 of Fig. 2;

Fig. 4 is a detail sectional view of the friction wheel and associated parts, said section being taken on the line 1 l of Fig. 3;

Fig. 5 is a detail side elevation of the friction shoe; and

Fig. 6 is a similar detail View of a slightly modified form of shoe.

Referring more in detail to the drawings, an angular pedestal or foot 10 is supported by a circular plate 11, there being interposed between said plate and the foot 10 a thrust bearing 12 of any desired construction. These parts are held in operative relation by Serial No. 6&7361.

means of a hollow cylindrical stem 13 carried by the plate 11 and extending upwardly through the bearing, the foot 10, and slightly above the latter, the upper end of said stem being provided with a removable head 14:. The under face of the plate 11 is pro- Vided with a layer .of felt 15 or other material having a high frictional coeliicient, this plate, when the device is in operative position, being designed to rest down upon turntable 16 of the phonograph and to rotate therewith, the hollow stem 13 being designed to receive the upstanding stud in the center of the turntable.

At one end the foot or pedestal 10 is upturned, as at 17. and is attached to and supports the large diaphragm frame 18. The foot may be attached to the frame by means of screws 19 or the like. and it is preferred in making this attachment to provide for slight bodily movement of the frame rela tively to its support, this being accomplished in the embodiment shown by providing a slot 20 in the upturned portion of the foot 10 for one of the retaining screws 19. In this manner it will be observed that the mechanism or unitsupported by the foot may oscillate within certain prescribed limits with respect to the support, this being to compensate for misalignment and any unevenness in the turntable top. The dia phragm frame 18 is provided with a central opening 21, surrounding which and projecting forwardly from the plate is a boss or neck 22 adapted to receive the outer free end of the tone arm 23 of the phonograph. The boss or neck 22 is apertured for receiving a retaining screw 24 or the like.

A large diaphragm 25 is securely clamped at its edges between circular gaskets 26 within the chamber 27 of the frame 18, this clamping of the diaphragm in place being effected by means of a rear plate 28 held in place on the rear of the frame 18 by means of retaining screws 29. The plate 28 is also centrally apertured, as at 30.

An arm 31, preferably carried by the rear plate 28, extends rearwardly from the latter and carries at its outer end an elongated bearing 32 in which is journaled a transverse shaft 33, the latter protruding beyond the hearing at both ends.

A bushing 8st flanged as at 35, is fixed to the inner protruding end of the shaft 33 by means of a retaining screw 36. The position of the bushing 34 on the shaft is such that the flange thereof abuts against the adjacent end of the bearing sleeve 32. This bushing 34 carries a friction wheel 37 composed of a resinous substance, such as amber or the like, having a high frictional coefiicient, the inner periphery of the wheel 37 being provided with a keyway 38 adapted to receive the key 89 carried by the bushing so that the wheel will be positively driven upon rotation of the shaft. The bushing is screwthreaded adjacent itsfouter end for the re ception of a nut- 40 which clamps the wheel .37 securely in position. v

The periphery of the wheel 37 is shown as 'V-shaped in cross section and is partially encompassed by a'friction strap or shoe ll, the confronting surface of which is correspondingly :tapered. The strap or shoe 41 is preferably of composite construction, being made in two layers, the inner layer 42, or layer which coacts with the wheel 37, being of a hard substance hi'rving a high fr' coeflicient, while the outer layer l3 th preferably composed of some soft substance Which will deaden or absorb extraneous noises transmitted .to the device. In practice, it has been found expedient to construct the inner layer-of the strap 41:1 of hard rul'rber and the outer layer thereof of soft rul her. It is also preferred to construct the strap or shoe in segments .4-1 and an pivoted together as at 4A. In this manner n'rore intimate .contact is obtained between the strap and the wheel throughout their contacting surfaces. The lower end of the strap or shoe is connected to the center of the large diaphra gm .25 by means of a link 4-.5. Carried by and extending rearwardly from the plate 28 of the diaphragm frame are a plurality ofarms 16 carrying adjacent their outer ends pivot screws 4L7, the latter pivotally supporting the freely-movable weight-arm 4:8. The weight arm 48 is slotted 21. 349, and pivotally mounted in t slot is lever arm 50, the pivotal point thereof being des ignated as 51. The inner end of the lever arm 50, or the end thereof next adjacent the diaphragm frame, is connected to the upper end of the strap or shoe d1 by means of link 52, this connection being such that the link '52 inclines downwardly and forwardly so that the maximum effectof holdi 't is shoe in firm engagement with the w eel 37 by means of the weight will be obta:

A large driving wheel 58 is the outer end of .the shaft 31 by a screw 54 passing through a boss o c llar 55 carried the wheel and into e ent with said shaft, The boss or cell when the Wheel 1s mounted, abuts I .in'st the outer end of the hearing sleeve so that all lateral play of the shaft is provided against, the flanged end of the h h. r

abutting against the other end of the bear. ingsleeve 32, as previously described. The

wheel is of such diameter as to contact through themedium of the connecting link 45. If the position of the shoe 41 remains undisturbed while the wheel a3 is being rotated, the friction between the wheel and shoe 37 and 4-1, respectively, will be substantially constant and the tension on the diaphragm will be equally constant. If,

however, the lower end of the inclined link he moved downwardly and slightly forwardly, or ii dly and slightly rearward ly from its not al positiom'thc effect will be to increase or decrease, respectively,-the intin'iacy of Contact between the rotating fric tion wieel and the overl ng shoe, t.erehy varying the tension ere ed upon the diapl'iragn'l 25 and causing it to quicklyassume new positions, producing inedible sounds.

Thus will be apparent that if the vibrations of the diaphragm of an ordinary receiver are accurately imores'sed upon. the lower end of the inclined link he same will be transmitted to the large diaphragm 25 and will be enormously amplified in this transn'iission through the coaction of the shoe and friction wheel.

Now, therefore, in order to transn'rit'or impress the vibrations .of the diaphragm of an ordinary telephone receiver upon the lower end of the link 52, the outer end 56 of the pivoted lever arm 50 is connected by means of a link 57 to the center of the diaphragm 58 of the telephone receiver 59, the la er being supported from the rear plate 28 of the large diaphragm frantic by means of sm all retaining screws (30. By this arrangement, it will be perfectly obvious that when the diaphragi 58 is vibrated the intimacy of contact between the friction members, will be correspondingly varied. and the vibrations of the diaphragm will correspond in frequency withthe vibrations of the .diaphragm 58, but their amplitude will be greatly enhanced and the sounds reproduced thereby will have been greatly magnified.

A cylindrical casing 61' slipped over the outer periphery of the frame 18, and re tained thereon by means of screws or the like, completely houses the entire mechanism, 'ght opening 62 being provided in they bottom of the casing to accommodate the lower expose, supporting elements.

In operation, as previously described, the unit is mounted on the'turntable of a phonograph with the upstanding post in the center of such table received within the hollow stem 13 carried by the supporting plate 11, the latter resting down upon the said turntable and the large driving wheel 53 contacting with the top of the table. The outer free end of the tone arm is slipped into theprotruding neck 22 of the frame 18 and made fast by means of the screw 24:, this connection serving also to hold the device stationar I when the turntable is rotated. Of course, as will be readily appreciated, the supporting plate 11, the lower ball race of the bearing 12, driving wheel 53 and parts driven thereby, all rotate upon the operation of the turntable, but the casing of the de-.

vice, including the frame 18 and all of the non-rotatable parts carried thereby, remain stationary.

It will be obvious to those skilled in the art that the present improvements may be operated by means other than a phonograph turntable. For instance, a motor could be connected directly to the shaft 31 of the device, or many other drives could be devised.

In Fig. 6 of the drawings, a slightly modified form of friction. strap or shoe is illustrated. The strap of this figure is shown comprising a number of segments pivotally connected together, as distinguished from one large segment having a small segment at tached to one end thereof, as shown in Fig. 5. Otherwise this modification is substantially the same as previously described.

A full-sized operative machine constructed in accordance with the present invention has been built and thoroughly tested. The results have been exceedingly good. With the telephone receiver of the device connected to the second stage of an ordinary two-audio frequency stage amplifier radio receiving set, entire programs broadcast from distant sending stations have been clearly and distinctly heard at a distance of one hundred and fifty yards from the device. Furthermore, and also of great importance, as will be appreciated by those skilled in the art, the quality of the reproductions, despite this enormous amplification, was extremely fine, the full timbre and tone being retained and faithfully reproduced. with an entire absence of all metallic, grating, rasping and other extraneous noises which so commonly accompany amplified reproductions of this charactor.

The susceptibility of the construction herein illustrated to changes and modifications will be readily apparent to those skilled in the art, and it is not therefore desired to limit or restrict the invention except where limitations appear in the appended claims.

I claim:

1. The combination with the motor-driven turntable of a phonograph, of an electromechanical sound reproducer and amplifier mounted thereon and supported thereby and provided with a rotatable driving element contacting with and driven by said table.

2. The combination with the motor-driven turntable of a phonograph, of an electro mechanical sound reproducer and amplifier mounted thereon and supported and operated thereby.

3. The combination with the tone arm and motor-driven turntable of a phonograph, of an electro-mechanical sound reproducer and amplifier mounted on and supported by said turntable and connected with said tone arm and provided with a rotatable driving ole-- ment contacting with and driven by said table.

4. In a device of the character described, primary and secondary diaphragms, and friction-producing means interposed there-- between, said means comprising a rotatable friction wheel and a segmental shoe contacting therewith, a weighted arm pivotally suspended above said wheel, a lever arm car-- ried thereby and connected to said primary diaphragm and to one end of said shoe, respectively, and a link connecting the other end of said shoe to said secondary dilaph r 21 gm.

5. In a device of the class described, primary and secondary diaphragms angularly disposed one with relation to the other, friction-producing means mounted above said primary diaphragm and to the rear of the secondary diaphragm, a weighted arm pivotally suspended above said friction-producing means with its free end directed toward said secondary diaphragm, means carried by said arm connecting said primary diaphragm to said friction-producing means, and a connection between the latter and said secondary diaphragm.

6. In a device of the class described, primary and secondary diaphragms, and friction-producing means interposed therebetween and connected thereto, said means comprising a rotatable friction wheel and a shoe contacting therewith, the latter having a relatively hard contacting surface and a relatively soft outer periphery.

7. In a device of the class described, primary and secondary diaphragms, and friction-producing means interposed therebetween and connected thereto, said means com prising a rotatable friction wheel and a segmental shoe contacting therewith, the segments being hinged together and each being of composite construction having a hard working surface and a soft outer surface.

8. The combination with a phonograph, of a rotatable support adapted to rest on the turntable thereof and having an opening therein to receive the centering post of said turntable, a frame carried by said support, primary and secondary diaphragms carried therewith, and means contacting with said turntable for driving said Wheel, said frame having an opening therein adjacent said secondary diaphragm adapted for connection to the tone .arm of said phonograph.

10. The combination With a phonograph, of a support adapted to rest on the turntable thereof and having an opening therein to receive the centering post of said turntable, a frame carried by said support, primary and secondary diaphragms carried by said frame, friction-producing means includ- 7 ing .a rotatable friction Wheel interposed hetween said diaphragms and cQ-Qperat-ing therewith, and means also carried by said frame and contact-ing'with said turntable for driving said Wheel, said frame having an opening thereinadjacent said secondary diaphragm adapted for connection to the tone arm of said phonograph, said support comprising a plurality of relatively rotatable parts, the connection between the tone arm and frame serving to prevent rotation of the latter and the upper partof said support rotatable friction Wheel interposed bet-Ween ,sald dia-phragms and co-operating while permitting "the lower part thereof to revolve with said turntable.

11. The combination with a of a frame, a plurality of diaphragms can:- r ied thereby, a shaft also carried by said frame, ,a friction wheel fixed :on said shafit,

a friction shoe contacting with said wheel and connected .to said primary and secondary diaphragms, respectively, a rotatable support for said. frame adapted .to rest upon the-turntable of said "phonograph and to vaevo'lye therewith, means to prevent rotation 10f said frame, and means carried said shaft and contacting with said table for rotating said Wheel.

12. The combination'vvith a 'honograph, of a frame, a plurality of diaphragms mmried thereby, a shaft also -.carr-ied by said frame, a friction Wheel fixed on said shaft, a friction shoe contacting with said wheel and conneoted'to said primary and secondary di'a phragms, respectively, a rotatable support for said frame adapted to nest npon the turntable of said phonograph and to revolve therewith, said frame having an opening therein adjacent said secondary diaphragm 3 adapted to receive the free end of the tone arm of the phonograph whereby utilization is made of the amplifying passages and horn of the latter and further whereby said frame is prevented from rotating with said support, and means carried bysaid shaft for contacting With said table" for driving said Wheel. a

In testimony whereof, I have subscribed my name.

CHARLES KK. onnerna. 

